Sleep training means using behavioral techniques to teach your baby to sleep independently by altering her “sleep onset associations” — or the circumstances your baby needs to fall asleep at bedtime. By removing your presence at bedtime, you are providing new associations with the result that she will learn to fall asleep independently, both at bedtime and when she awakens during the night.
Thank you for checking out The Baby Sleep Site! I’m sorry to hear you’re having so much trouble with sleep. Based on your comment, it does sound like your little one might be coming into the 4 month sleep regression. We have an article with a lot of information on that here: https://www.babysleepsite.com/baby-sleep-patterns/4-month-sleep-regression/
First, let us introduce you to Melissa, mom of 6 month old Theo (@mohrlivingmama on Instagram). After struggling with sleep training, Melissa offered to share her personal story and best tips for other moms thinking of giving sleep training a try. Since it's always most helpful to hear from a mom who's been there, throughout our Sleep Training Guide Melissa will be sharing what worked for her and her son during sleep training. 
Prepare yourself for a few difficult nights. Hearing your baby cry can be excruciating, as every parent knows. During the waiting periods, set a timer and go to a different part of the house, or turn on some music, so you don't have to hear every whimper. As one BabyCenter parent says, "The first week could be rough. Try to relax and know that when it's all over, everyone in your household is going to sleep more easily and happily."
“There are many variations to any sleep training method. For example, you can do a cross between The Chair Method and PUPD with great success and fewer tears! There are also ways of breaking each method into smaller baby steps, which we recommend very often in our Personalized Sleep Plans®. Find what feels tolerable (because, frankly, no one ‘likes’ to sleep train), more comfortable for you, and what seems the gentlest, yet effective, on your baby, depending on his or her temperament and personality.”
As we previously mentioned, introducing healthy sleep habits and routines as early as possible will help significantly during sleep training. If you haven’t already, try to establish a bedtime routine before you start sleep training baby — this will encourage healthy baby sleep patterns. This should be a series of soothing activities that help to calm your baby and prepare them for sleep - things like swaddling, bathing, and rocking usually work well, but every family’s routine will look different.
• Know there will be regressions. Teething, illness, vacation and routine shifts all can lead to poor sleep, and that’s all right, Vance says. “Often, you may have to go back to training for a day or two to get back on track, but you won’t lose ground. If your child has been trained to be a good sleeper, one week off schedule because of vacation won’t change that.”
Typically, formula-fed infants who are growing well no longer need to feed at night by 6 months. Breastfed infants may continue a little bit longer, but typically no longer feed at night by 9 months. If your baby has been falling asleep independently at bedtime for a month but still waking to feed, you may want to consider weaning at night. Be aware that if you are breastfeeding, this may lead to a reduction in milk supply.
Some of these experts think cry it out methods are not good for babies. Pediatrician and "attachment parenting" advocate William Sears devotes an entire chapter of The Baby Sleep Book to a critique of cry it out approaches. Sears, along with no tears advocates such as Elizabeth Pantley (author of The No-Cry Sleep Solution), believes that cry it out techniques can give your child negative associations with bedtime and sleep that could last a lifetime.
• Weissbluth method. This sleep-training method suggests you set up a bedtime routine (bath, book, lullaby), then put baby to sleep, shut the door and don’t re-enter until the next morning. “I tried this, and the first night was awful,” says Jen, a mom of one, who did the Weissbluth method at 4 months. “I turned on the shower and sat in the bathroom so I wouldn’t hear my son cry. But I was watching the baby monitor and saw that after an hour, he found his thumb and fell asleep. The next night was maybe 40 minutes of crying, then 20 minutes the night after that. He’s always happy in the morning, and I feel this was the right choice.”
Parents are often hesitant to go this route, worried about how much crying will be involved. While McGinn doesn’t deny it can be difficult at first, she finds parents are often surprised by how quickly it works. “Yes, there is a lot of crying, but it’s short term,” she says. “You might get a lot of crying for two to three nights, but then every night is less and less.” She says you should see significant improvement with this method by night three or four but adds that it’s important to try it for a week before determining that it’s not working.
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